.sider {
  box-shadow: 2px 0 4px #88888823;

  display: flex;
  flex-direction: column;
  height: 100vh;

  position: relative;
  .demo_logo_vertical {
    height: 70px;
  }
  .menu {
    height: 100vh - 20vh;
    overflow-y: auto;
  }
  .btn {
    position: absolute;
    bottom: 0;
    right: 0;
    height: 64px;
    display: flex;
    justify-content: center;
    align-items: center;
  }
}
.menu::-webkit-scrollbar {
  width: 0px; /*  设置纵轴（y轴）轴滚动条 */
  height: 0px; /*  设置横轴（x轴）轴滚动条 */
}
.menu::-webkit-scrollbar-thumb {
  border-radius: 10px;
  box-shadow: inset 0 0 5px rgba(0, 0, 0, 0.2);
  background: rgba(0, 0, 0, 0.2);
}
/* 滚动条轨道 */
.menu::-webkit-scrollbar-track {
  border-radius: 0;
  box-shadow: inset 0 0 5px rgba(0, 0, 0, 0.2);
  background: rgba(0, 0, 0, 0.1);
}
/* hover时显色 */
.menu:hover::-webkit-scrollbar {
  width: 4px;
  height: 4px;
}
